You may have had your own tears, and understandably so. Late Blight of potatoes and tomatoes was the disease responsible for the Irish potato famine in the mid-nineteenth century. Spores are spread by rain/watering splash, insects, and wind, and through our hands and tools and through these mediums they can travel distances. Spore spread is most rapid during conditions of high moisture, marine layer days, and moderate temperatures, 60°-80°F. Once established, the fungi can over-winter in your garden soil, on debris and weeds.

Fusarium Wilt is commonly found throughout the United States, is a soil and wind-borne pathogen. Plants susceptible to Fusarium Wilt are cucumber, potato, tomato, eggplant, pepper and beans. Fusarium wilt causes foliage to yellow, brown spots on leaves, leaves to curve the length of the leaf, wilt, then turn brown and die. Your plants become stunted because they can no longer function properly.

Verticillium wilt is most active in humid climates. Cool nights and moist conditions, the kind that favors peas, tend to encourage it. It is windborne and lives in the soil, entering plants through the roots and is drawn up to stems, leaves and fruit through water uptake. At the same time, it is robbing the plant of moisture. The first symptoms of Verticillium are usually seen in wilting, yellowing and curling leaves. Discolored streaks are often seen in strawberry stems and runners, and in berry canes. Get resistant strawberry varieties like Seascape.

To determine if a plant is infected with bacterial wilt, press together two freshly cut sections of a stem and slowly pull them apart. If a “stringy” sap (bacterial growth and associated resins) extends between the cut ends, the plant has bacterial wilt.

Especially Tomatoes! And of those, Heirlooms are particularly susceptible to the wilts. Instead, get varieties that have VFN or VF on the tag at the nursery. The V is for Verticillium, the F Fusarium wilt, N nematodes. Ace, Early Girl, Champion, Celebrity, are some that are wilt resistant/tolerant. In these drought conditions, consider getting only indeterminates. In the Mother Earth News tomato survey, they found gardeners chose heirlooms over hybrids if their soil is wilt/blight free. Otherwise, the longer the gardener has gardened, they more they chose wilt resistant hybrid toms if their soil has the fungi.

Western striped cucumber beetles (on right in image) are deadly to cucumbers. They are referred to as ‘plant-wounding insects’ and also transmit bacterial wilt. Feeding on blossoms and leaves, they also spread it among squash, melons, and pumpkins which in turn spread it to nearby tomatoes. Cucumber beetles also vector viruses such as cucumber mosaic but do so much less efficiently than aphids. Spiders are one of the predators that eat the beetles. Let those spiders live! A tachinid fly and a braconid parasitoid wasp parasitize them. Grow plenty of flowers for these beneficial insects!

Radish have become my new religion! Radish repel the beetles! Best to plant your radish ahead of installing your transplants or have it up before the seedlings start growing from seed. Grow your radish companion along where you will let the vine travel, among squash and pumpkins, cucumbers and TOMATOES! The part of the vine growing up over an arch or up a trellis won’t be helped, so if you have space and uninfected soil, you may opt to keep your vines on the ground. If you do have infected soil, but choose to keep your vine on the ground, keep that area weeded and don’t lay on mulch. Weeds and mulch keep soil moist. The fungi dry and die on hot dry soil. Water only where you staked, at the planting basin. Plant enough radish so you can eat some, but as a beetle repellent, let it grow out so the whole plant is big and protecting your cukes, tomatoes and other vines.

Broccoli also repel cucumber beetles. Grow cucumbers under over summering Broccoli. Put in plenty of straw mulch to keep the brocs cool and the cukes off the ground. Whenever you see these beetles don’t fall for how cute they are. Anticipate how they drop to the ground when you reach for them so approach from below, hand open. Catch & Squish.

Transplant rather than direct seed! Tiny seedlings are most susceptible to cucumber beetle feeding damage and to bacterial wilts.

Apply straw mulch an inch thick! No more than that. You want light and air circulation, for the soil to dry some. Washington State Extension says: Straw mulch can help reduce cucumber beetle problems in at least 3 different ways.

Second, the mulch provides refuge for wolf spiders and other predators from hot and dry conditions, helping predator conservation.

Third, the straw mulch is food for springtails and other insects that eat decaying plant material; these decomposers are important non-pest prey for spiders, helping to further build spider numbers.

It is important that straw mulch does not contain weed seeds and to make certain that it does not contain herbicide residues which can take years to fully break down.

Cucumber Beetles have their preferences! Bitter is their favorite. Not interested in watermelon at all, but watermelon does get the wilts, just from other sources! Anyway, see more details and rankings of varieties of different kinds of veggies. Varieties make a huge difference.

Long story short, less C Beetles, less Wilts = healthier Tomatoes!

Special Planting and Growing Tips!

Regarding soil fungi like Fusarium and Verticillium wilts/fungi, how you care for cukes and toms is super important! Cucumbers are even more susceptible than tomatoes to the wilts fungi, die pretty instantly, in about 3 days when they get infected. So when you plant them, treat them similarly to your tomatoes if you have wilts fungi in your garden.

Plant cukes and toms on a raised mound/basin with the bottom of the basin above the regular soil level. This allows good drainage. Make the basin low area as big as you tom’s feeder roots will grow to. Once planted, top the bottom of the basin with a 1/2″ of compost, cover that with only 1″ of straw to let in air and sun to dry the soil. Keep the LEAVES OFF THE GROUND from the get go. Leaves touching the soil is the main way toms get the wilts. Remove lower leaves that might touch soil when weighted with dew or water from watering. Keep a regular watch for new foliage sprouting at ground level and remove it on sight! AVOID WATER SPLASH when watering at ground level. The fuzzy damp leaves of toms and eggplant are perfect fungi habitat.

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When your toms are about a foot tall, waterneighboring plants, but not your toms. That keeps the soil drier near your plant, so the fungi can’t thrive there. Since toms have a deep taproot, they will get plenty of water from what you give neighboring plants. Water near them but not at them or on them. In fact there are farmers who dry farm tomatoes! Read more!

If you are comingling beans withcukes lower along a trellis, plant the beans between the raised cucumber mounds. Beans don’t get the wilts, but love the water, so lower is good. They are a big plant with continuous high production and short roots that need to be kept moist. Mulch ASAP with straw under cukes to keep leaves and fruit off the ground, and out of the insect zone. Put a tall enough stake in the middle of each basin so you know where to water later when the leaves get big and cover the area. Water gently BELOW the leaves at ground level, no splash. Keep those leaves dry. When your plant gets big enough you can remove lower leaves.

Since the fungi are airborne as well as soil borne, plant in different places as far apart as possible. Plant so leaves of one plant are not touching another plant. Remove sickened foliage ASAP to reduce fungi population and slow spreading. Prune on hot, dry, unwindy days, mid morning to midday, after dew has dried, so cuts can dry and heal with less chance of airborne fungi getting into them. Try not to touch the cuts after they have been made. Use clippers for a clean cut. Wash your hands often, dip your tools in alcohol. Trimming away infected leaves is a sad and tedious process. It’s practically impossible not to spread the fungi as you touch leaves that have it and try to remove them without touching any other stems or leaves. The very cuts you make are open to fungi. Then, naked stems are susceptible to sunscald – see image below. You come back a few days later and more leaves are wilting. The disease is internal, has spread out to the leaves. At some point soon after that, a lot of gardeners pull the suffering plant. It’s done. Not good to leave it and let windborne fungi infect neighboring plants. Do not compost infected plants or trimmings. The fungi has amazing survival ability and being soil borne, it is right at home in your compost. Put it in the trash, carefully bagged so as not to spread or leave any trace. Wash your hands. If you can, burn the infected plants on a non windy day.

The wilts can’t be stopped. Sooner or later the plant leaves curl lengthwise, get the dark spots, turn brown then blacken, dry and hang sadly. Plants can produce but the fruit doesn’t ripen properly if it does produce. It’s agonizing to watch. Sometimes they somewhat recover later in the season after looking totally dead. You had stopped watering them, summer heat dries the soil and kills enough of the fungi for the plant to be able to try again. But production is so little and fruits don’t ripen properly. It’s better to pull it, reduce the fungi population that can blow to other plants. The safest bet is to remove the entire plant. Get all of the root as best you can. The root is where the wilt’s mycelium first congregate and infected roots left in the ground will start the whole process again. Replant in a different place if possible.

Apply to newly installed transplants, and during the season every 2 to 3 weeks, so new growth will be covered. Wet both the undersides and tops of leaves. Per gallon add:

One dissolved regular strength aspirin

1/4 Cup nonfat powdered milk

Heaping tablespoon baking soda

1/2 Teaspoon mild liquid dish soap

After the tomatoes set, add some Nitrogen. Boost your plant’s immune system with some worm castings at the same time. You don’t want to add too much nitrogen to your tomatoes before they set fruit. Too much nitrogen before fruiting leads to more leaves and less fruit. Add N only once. Stressed plants are the most susceptible to the fungus. Water regularly and deeply. Use well-balanced, slow-release organic fertilizers that aren’t overly heavy with nitrogen. Alfalfa pellets will do the job. A healthy plant tends to fight off the spores.

Blight can also be transmitted through seed, so NO seed saving from infected plant fruits. Fresh seeds from a safe source and resistant varieties are in order.

Remove volunteertomatoes and potatoes. If they are a not a resistant or tolerant variety, when they get sick, they increase the chances of your resistant varieties having to fight harder to live, and your good dear plants may not win the battle.

Air circulation, plant staking and no touching. Air circulation allows the wind to blow through your plants. This allows the timely drying of leaves and it helps break up micro climates. If your plants are packed too tightly together, they themselves become barriers to drying. Staking your plants to poles and using cages helps them grow upright, creates gaps between the tomato plants. Thin growth inside the cage if the leaves get too dense. You want wind and sun to reach through and around your plants. Moisture is needed for fungi to spread. Dry is good. Tomatoes should be planted with enough distance that only minor pruning is needed to keep them from touching each other.

Spray proactively. Wettable sulfur works. It is acceptable as an organic pesticide/fungicide, is a broad spectrum poison, follow the precautions. It creates an environment on the leaves the spores don’t like. The key to spraying with wettable sulfur is to do it weekly BEFORE signs of the disease shows. Other products also help stop the spread. Whatever you select, the key is to spray early and regularly.

At the end of the season remove all infected debris,don’t compost or put in green waste containers. Bag it and trash it. Don’t leave dead tomato, eggplant or peppers in the garden to spend the winter – especially if you are in a community garden. Pull weeds because spores can over-winter on weed hosts. Many weeds, including dandelions and lambsquarters, are known to host Verticillium wilt. During our winter season, turn your soil about 10 inches deep. Let the soil dry and the fungi die. Burying the spores helps remove them, it disturbs cucumber beetle eggs and exposes snail eggs to die!

If you have space, crop rotation is an important tool in fighting wilt. If you’ve had trouble with wilt, don’t plant potatoes, eggplant, or other Solanaceous vegetables where any of them have grown for at least four years.

Practice prevention, be vigilant. If you don’t have wilts in your soil you are so blessed!

The Green Bean Connection started as correspondence for the Santa Barbara CA USA Pilgrim Terrace Community Garden. All three of Santa Barbara city’s community gardens are very coastal. During late spring/summer we are often in a fog belt/marine layer most years, locally referred to as the May grays, June glooms and August fogusts. Keep that in mind compared to the microclimate niche where your veggie garden is. Bless you for being such a wonderful Earth Steward!

Healthy Practices Make a Difference!

Plant in full sun!
Plant so leaves of one plant don’t touch another and spread the spores.
Remove any debris or dead leaves breeding habitat.
Remove and don’t compost infected leaves. If you don’t remove them, you reinfect your plant each time you water.
Wash tools and your hands before you go from one plant to the next.
Water in the AM, at ground level. No overhead watering.
BEFORE you have mildew, while your plants are still babies, drench the leaves with a baking soda/milk mix. Tablespoon Soda, ¼ cup nonfat milk powder, drop of liquid dish detergent in a watering can.
Drench weekly with your mix. But if you think you aren’t going to be able to get rid of the mildew, sadly, do the one cut prune. Remove that plant so it won’t infect others – yours or your neighbors’. Do this sooner than later. Mildew is windborne, so the more mildew, the more is spread.